Separation of hydrogen-methane mixtures by electrochemical hydrogen compressor: Experimental and modelling investigation on the influence of different Nafion membranes and operative conditions

The electrochemical hydrogen compressor (EHC) offers an effective solution for hydrogen transport challenges, enabling simultaneous purification and compression, even when hydrogen is blended with natural gas at low concentrations. This study investigates the impact of three commercial Nafion® membrane types (Nafion® 117, Nafion® 115, and Nafion® 212) on the separation efficiency of EHC, examining the influence of temperature, methane concentration, and hydrogen flow rate, thereby providing a comprehensive evaluation of membrane-specific performance on the EHC's efficiency. Nafion® 212 demonstrated superior energy efficiency due to its lower thickness and higher ion-exchange capacity. Tests with a 90:10 methane:hydrogen molar ratio revealed an energy consumption of 2.30 kWh·kg−1H2 and hydrogen purity exceeding 99 %. The experimental results were validated with a mathematical model incorporating key parameters from existing literature, achieving an average deviation of 2.5 % between the model and experimental data.